Blog post 7 - February Updates!
Over the past two weeks, February 5 - February 19, 2022, our team has received all our components(except the radio transmitter-console for the drone). With the arrival of all materials, we are able to test out our components and check some of the specifications not provided online.
Motor Control Testing:
Using a Flywoo NIN 1404 V2 Ultralight FPV Motor, a test rig was built using 3D Printed Parts, a 4s Lipo battery and an Arduino.
Figure 1: Test Rig for the Motor
Using the Arduino, data was collected to measure the Throttle Vs. Thrust.
Figure 2: Graph testing Throttle[%] Vs Thurst [g]
From the preliminary data, the middle range(30%-50%) is where most drone maneuvers such as hovering, will be done. This data looks as expected, however, the peak thrust (up and down from the side view of the drone) looks a little less than expected and more costly in terms of power. We'll know more details by modifying the test rig.
These modifications are a result of having the 3D Printed objects being designed for a larger motor. This modifies the setup for the motor testing. Hence, for the next trial, we will print another 3D Part, however, due to the 3D printers malfunctioning and being used by others, delays have occurred and we hope to accomplish this next week.
Future analysis from the motors is obtaining thrust, voltage, current, and throttle from 0% to 100%.
Overheating of the Box:
For thermal issues that came from electrical components(especially the video transmitter), some members of the electrical and mechanical team had found specifications of the electrical components, such as area of chip, voltage, current, and power to calculate the area needed for a heat sink. Calculations for the heat sink are necessary to dissipate the heat of all the components. This was done with the help and advise of Dr. Hadi Ghasemi, an expert on Thermodynamics, Heat transfer and Nanotechnology.
This image is only available upon request only by parties from the University of Houston Cullen College of Engineering
Figure 3: CAD Design for the Electrical Box
A CAD design was made for the electrical team to know how the electrical components will be placed within the box and know how the box will be structured. A plan on building an electrical schematic is for the upcoming weeks. We needed weights to get a better design to which the center of mass towards the center of the drone, so now with those measurements we can get an accurate reading.
Measuring all the Components Weights:
This image is only available upon request only by parties from the University of Houston Cullen College of Engineering
Figure 4: Results from Measuring Components Weight
Precise weight of all components were measured. Future objective is to measure and calculate power.
Simulations:
This image is only available upon request only by parties from the University of Houston Cullen College of Engineering
Figure 5: Final Simulation Result for Stability Settings
Simulation settings were refined and an appropriate flight stability for beginner pilots was determined for when they fly indoors. Based on simulator testing from Velocidrone, we were able to get accurate measurements for optimized movement.
On-Board Computer Software Programming:
C++ can now run using the Raspberry PI Zero. Some of the testing going on is parallel processing with Python. The result was that it got a slight FPS boost. Some improvements were made to build a better test bench system to collect data using statistics(such as std and average instead of purely through observation). This required programming to have the first 50 frames taken and discarded to warm up the camera and the next 50 frames will have its FPS stored and analyzed. This is demonstrated in Figure 6.
Figure 6: Frame rate data from OpenCV with heavy build.
Future Progress is to get C++ OpenCV installed. More information about our progress on the drone's onboard computer software can be found in this link:
Overall Challenges:
Some of the potential difficulties we might face in the future are weight and thrust constraints of the drone. In order to solve this issue, some of the solutions we have thought about is reducing the weight of the entire drone, by possibly reducing as much weight from the mechanical and electrical side of the drone. We are also thinking of adding propellers with a larger amount of blades to it(6 instead of 4) to increase thrust. This poses risk in potential design changes for the drone, but we hope to mitigate those challenges soon.
Thank you for reading our blog post!
Limited Technologies Team